Air conditioning system



Aug. 26, 1941. A. B. NEWTON `AIRCONDITIONING SYSTEM.

Filed Dec. 28,' 1939 OUTSI DE w4%0000000 u du -fl A- Ess -To wA-rsn vAws Fi f 'l ,'npentor Alwin. Nzwtom conditioned zones 5, 6, and 1,.

Patented Aug. 26, 1941 2,254,185 Ara CONDITIONING SYSTEM Alwin B. Newton, Minneapolis, Minn., assigner to Minneapolis-Honeywell Regulator Company, vMinneapolis, Minn., a corporation of Delaware Application December 28; 1939, Serial No. 311,388

4 Claims.

invention relates in general to air conditioning and more particularly to automatically' controlled combined heating and cooling systems.'

Itis an object of this invention to provide a summer-winter air conditioning system in which a stream of relatively cool air and a stream of relatively warm air are supplied simultaneously to a conditioned space, the proportions of the streams being controlled automatically ta maintain the desired temperature, and in which the humidity of one of the streams is varied under the control of a humidity Aresponsive device for maintaining the desired humidity in the space.

A further object of this invention is the provision of a system having warm and cold plenum chambers connected by individual ducts to a plurality of zones, with a simple and eiective arrang-ement for individually controlling the humidity of the air being supplied to the various zones for thereby maintaining desired humidity conditions in each zone.

Another object of this invention is the provision of a system for individually controlling the J description and the appended claims.

For a full disclosure of this invention, reference is made to the following detailed description and to the accompanying drawing in which:

Figure 1 is a sectional View of the conditioner and which diagrammatically indicates the controls,

Figure 2 yis a top view of the conditioner and ducts of Figure 1,

Figure 3 is a diagrammatic view of a portion of a modification of Figures 1 and 2.

Referring to the drawing, reference character I A indicates an air conditioner which is connected by individual supply ducts 2, 3, and 4 to the The conditioner I is of the push throug type havingV a fan 8 connected to the inlet thereof. This fan is provided with. -an inlet duct 9 which leads from return duct work, not shown, for; delivering returnl air from the zones 5, 6, and 'l to the con# with a fresh air inlet for thereby supplying fresh air for ventilation purposes.

'I'he conditioner I is divided by a horizontal partition I into a heating chamber II and a' cooling chamber I2, these chambers extending the full width of the conditioner.v is provided withv a heating coil I8 which extends the full width of the conditioner as shown in Figure 2 Aand which is provided with an inlet point of the thermostat 2| in accordance with valve I4 which controls the flow of heating me. dium into this coil. The valve Il is lpositioned by a proportioning motor 'i5 which is controlled by means of a thermostat I6 responding to the temperature of the air heated by the coil. This .thermostat serves to open the valve upon a fall in air temperature and to close the valve upon a rise in this temperature. The thermostat I6 is adjusted by means of an outside thermostat I1 which serves to adjust. the control point of thethermostat I6 in accordance with outside temperature. This thermostat I1 acts upon a fall in outside temperature to raise the setting of thermostat I 6 so as to supply warmer air from the coil I3. Preferably, the thermostat I1 is arranged so that when outside temperature rises to it sets the thermostat I6 to maintain a temperature of '70fleaving'the heating coil. By this arrangement during the cooling cycle, the steam valve I5 will usually be closed entirely. The details by which thermostats I6 and I'I control the valve I5 do not form a part of this invention. For a disclosure of the details, reference is made to the Haines Patent No. 2,173,331.

In the cooling chamber I2 isy located a coolin coil I8 which extends the full Width of the conditioner similarly to the coil I3. This cooling coil is provided with an, inlet valve I8 which is positioned by a propotioning motor 20 under the control of a thermostat 2| responding to the temperature ofthe cool air discharged from coil I8. The 'motor 28 is also controlled by an outside thermostat 22 which serves to adjust the control outside temperature. This thermostat 22 upon a r-ise in outside temperature acts to lower the control point of thermostat 2I so that colder air is discharged from the coil I8. 'I'his thermostat 22 may be arranged so that when outside temperature is at 50 it adjusts the thermostat 2| so as to maintain the temperature of the cooled air at .v By this arrangement, whenoutside 'temperature falls below 50, the valve I9A for the cooling coil will be maintained closed.

The conditioner I is divided near itsbutiet edd by means of vertical partitions 24 and 25 (Figure Chamber I I 2) into damper passages 25, 21 and 22. The damper passage communicates with the duct 2, the damper passage 21 communicates with the duct t and the passage 2li communicates with the duct t. These damper passages are each provided with dampers 2li, 32 and 3|', the damper 30 being shown in Figure 1. 'I'hese dempers are all alike, each consisting of a rst set of blades 32 controlling the passage of cool air from chamber I2 and a second set of blades 33 controlling the flow of warm air from chamber li of the conditioner. These two sets of blades are connected together by means of an actuating member 3! which causes these dampers to move in opposite manners. Thus as the flow of air from chamber il is increased, the ow of air from chamber l2 is decreased and vice versa. The dempers 29, 3u and 3| are individually actuated by means of proportioning motors 35, 35 and 31. The motor 35 -ls controlled by a thermostat 38 located in zone 5, the motor 36 is controlled by a thermostat 33 in zone 6, and motor 3 1 is controlled by a thermostat ill in zone 1. By the arrangement just described, it will be apparent that the thermostats 38, 39 and 40 control the proportions of warm and cool air from the chambers and l2 of the conditioner, these proportions being varied in a manner to maintain the temperature at each zone constant. For example, if the temperature in zone 5 rises, the thermostat 39 will cause the motor 35 to position the damper 30 for decreasing the proportion of warm air supplied by chamber ll and increasing the proportion of cool air supplied by chamber l2. Upon a decrease in temperature in the zone 6, the opposite action will occur for thereby increasing the temperature oi' the air supplied to the zone.

In order to provide control of the humidity, the heating chamber Il is subdivided by a horlzontal partition 4| which extends the entire width of the conditioner l. This partition 4| divides the chamber Il into a humidifylng chamber 42 and a by-pass chamber 13. In the humidifying chamber d2 is located a humidifier which is illustrated as comprising a plurality of spray pipes 4t, this humidifier extending the full width of the conditioner I as shown in Figure 2. While partition ,il is shown for purposes of illustration as a iiat wall, it is to be understood that in an actual installation, `it would take the form of a trough r with a drain leading therefrom.

It will be noted that the vertical partitions 24 and 25 terminate short of the humidier 44 so that air passing through any portion of this humidifier can pass into any one of the chambers 26, 21 and 28. In order to control the humidity of the air supplied to each zone, passages 26, 21 and 28 are provided with humidity control dampers 45, 46 and 41, damper 46 being shown in Figure 1. Each of these dampers consists of a first set of blades 48 for controlling the flow of air from the humidifying chamber 42 and a second set of blades 49 for controlling the iiow of air from the by-pass chamber 43. These two sets of blades are connected so as to be operated in unison but oppositely by a proportioning motor. Thus the damper is positioned by a proportioning motor 50, damper 46 is positioned by a motor 5|, and damper 41 is positioned by a, motor 52. The motor 50 is controlled by a humidity controller 53 located in zone 5, motor 5| is controlled by a humidity controller 54 in zone 6, and motor 52 is controlled by a humidity controller 55 in zone 1.. By this arrangement, each humidity controller serves to position its correaaai-,ist

spending damper for varying the proportions of humidied and icy-passed air supplied to 4its zone and in this manner controls the humidity of the air therein. For example, if the humidity in zone t rises, the controller 54 will cause the motor 5| to position the damper 4l' in a manner to increase the ow of air through the by-pass 43 and decrease the amount of air taken from the humidier chamber 42. When the humidity in zone t is above the control point of controller 5d. the controller 5i will position the damper 41 for causing it to admit only air from the by-pass chamber t3 -into the passage 21. Thus at this time no humidlfled air is supplied to the zone 6. The humidity controllers 53 and 55 of course operate in the same manner upon their respective dampers.

When the humidity controller of each zone is satisfied, it is desirable to place the humidifier Ml out of operation. In order to obtain this action, the humidity control proportioning motors 50, 5| and 52 are each provided with auxiliary switches 56. These switches are each adjusted so as to open Whenever the corresponding damper i`s positioned for preventing iiow of air from the humidifier chamber while-closing when its damper is positioned for permitting air to ilow from said humidifled chamber. These switches 5B are connected in parallel to the Water valve 51 which controls the flow of water to the humidifier. By this arrangement, when all of thel'i'umidity controllers are satisfied, the water valve 51 is closed, but whenever any one humidity controller calls for humidlfying, the valve 51 will be opened.

With the arrangement shown in Figures 1 and 2, the damper blades 33 are completely closed upon the thermostat of that zone calling for the maximum amount of cooling. This prevents any humldiiled air from being supplied to the zone. In most cases, this is not a disadvantage since humidication will not be needed during the cooling season. In certain localities, however, humidilcation may be required even when maximum cooling is necessary. In such case, the humidifier damper motors may be provided with switches for inserting suitable resistance into the thermostat circuit for insuring that at least a minimum amount of Warm air is supplied to a zone upon call for dehumidiflcation.

Such an arrangement is shown in IFigure 3. A further auxiliary 'switch 65 is associated with the motor 5|. 'I'his auxiliary switch 65 is adjusted to open whenever the blades 48 are open to admit air to flow through the humidifier chamber and to close Whenever the blades 48 are closed.

A variable resistance 56 is inserted in the connection between thermostat 39 and damper motor 36. As longA as this resistance is in the thermo-l stat circuit, the damper blades 33 cannot be completely closed. The auxiliary switch 65 is connected to the resistance 66 by conductors 61 so as to shunt the resistance 56 when the switch is closed. Thus as long as hurnidostat 54 is calling for humldication, the damper blades 33 cannot be closed. For a more detailed description of the operation of such a minimum position resistance and associated switch, reference is made to the patent to George D. Kingsland, No. 2,123,428, of July 12, 1938.

A similar auxiliary switch and resistance is associated with the control equipment of each ot the other zones. Thus, with the arrangement of Figure 3, it is possible to obtain humidication of the air regardless of the demand for cooling.

From the foregoing description, it will be apparent that each zone thermostat serves to position its corresponding damper for controlling the proportions of cool and warm air supplied to its zone in a manner for maintaining the'zone at constant temperature. During the summer, the

outside thermostat I'I will adjust the discharge thermostat I6 for a temperature which is lower than the return air temperature and consequently this thermostat will be -satised without causing v the heating valve I4 to open. At this time,. the outside thermostat 22 Will adjust the control point of the discharge thermostat 2| for lowering the temperature of the air leaving the cooling coil I2 upon increase in outside temperature.

During intermediate seasons the thermostats I1 and 22 will adjust the thermostats I6 and 2| so that both the heating coil I3 and cooling coil I2 operate to some extent thereby permitting some zones to receive air for cooling and other zones to simultaneously receive air for heating. During the winter the thermostat 22 will adjust thermostat 2I so that the cooling coil I2 is out of l operation and the thermostat lI'I will adjust the discharge thermostat I6 so as to supply hotter air as outside temperature decreases. At all times the humidifier 44 canbe loperated whenever the humidity in any one zone becomes too low. Whenever the humidiiier is operating, the humidity controllers by varying the proportions of humidied and unhumidiled air withdrawn from the conditioner, will maintain the proper humidity in each zone.

While I have shown and described but a single A form o f invention, it will be apparent that many changes' may be made without departing from the scope thereof. It is therefore desired t be limited only by the scope of the appendedl claims.

I claim as my invention:

1. In an air conditioning system for a plurality of zones, in combination, rst air supply means for providing a supply of. relatively warm air, second air supply means for providing a supply of relatively cool air, individual duct means leading from said rst and second air supply means to said zones for supplying simultaneously both cool and warm air to said zones, individual ilow control means interposed between said rst and second air supply means and said individual duct means for controlling the proportions of cool and warm air passed into said individual duct means,

said cool and Warm air being mixed in said individual duct means to form individual streams of air for said zones which vary in temperature in accordance with said individual ow control means, individual zone thermostatic means for controlling corresponding ilow control means, means for dividing the warm air of said iirst air supply means into first and second streams prior to mixing in said individual duct means, means for humidifying said iirst stream, individual damper means for controlling the proportions of said rst and second streams entering each individual duct means, and individual moisture responsive devices influenced by the moisture content of the air in said zones for controlling corresponding individual damper means.

2. In an air conditioning system for a plurality of zones, in combination a first plenum chamber,l heating means for heating the air in said first plenum chamber, a second plenum chamber, cooling means for cooling the air in said second plenum chamber, rst and second thermostatic means for controlling the temperature of the air in said rst and secondplenum chambers, individual duct means leading from said rst and second plenum chambers to said zones for supplying simultaneously both cool 'and warm air to said zones, individual ilow control means interposed between said first and second plenum chambers and said individual duct means for controlling the proportions of cool and warm air passed into saidindividual duct means, said cool and warm air being mixed in said individual duct means to form individual streams of air for said zones which vary in temperature in accordance with said individual flow control means, individual zone thermostatic means for controlling corresponding flow control means, means for dividing the air of said rst plenum chamber into first and second portions common to all of said individual duct means, a humidier for humidifying the air of one of said portions, individual damper means in the individual duct means for controlling the proportions of said ilrst and second portions passed into said individual duct means, and individual moisture responsive devices influenced by the moisture content of the air in said zones for controlling said damper means and said humidifying means.

3. In an air conditioning system, in combination, means for providing aV stream of relatively warm air for supply to a conditioned space, means for providing a stream of relatively cool air for supply to said space, thermostatically controlled means iniluenced by the demand for heating o. cooling in said space for varying in a modulating manner the proportions of said warm air stream and the cool air stream supplied to said space for maintaining a-predetermined temperature in said space, means for dividing one of said air streams into first and second portions, means for changing the moisture content of the air in one of said portions, means influenced by the humidity of the air in said space for controlling said last mentioned means, and means controlled by said humidity inuenced means for preventing said thermostatically controlled means from completely interrupting the flow of Warm air to said space when there is a demand for humidication.

4. In an air conditioning system, in combination, means including heating means for providing a first stream of relatively warm air for supply to a conditioned space, means including cooling means for providing a second stream of relatively cool air for supply to said space, thermostatically controlled means influencedl by the temperature of said space for controlling in a lmodulating manner the proportions of the ilrst permitting .a now of the humidiiied portion of said warm air stream.

ALWIN' B. NEWTON. 

